Vattanasilp, W., P. Pungsuwan, T. Kongnaka, P. Kaenpakdee, U. Katiyajan, and T. Ngamsanit. “Tentative shortening lower limp muscles in non ambulatory cerebral palsy”. Archives of Allied Health Sciences, vol. 14, no. 3, Sept. 2002, pp. 218-29, https://he01.tci-thaijo.org/index.php/ams/article/view/65978.